return url:
/example-return?token=<token>
url-encoded:
%2Fexample-return%3Ftoken%3D%3Ctoken%3E
key url: /dev/public-key.pem
start:
/dev/login?return-url=%2Fexample-return%3Ftoken%3D%3Ctoken%3E
key url: /public-key.pem
start:
/login?return-url=%2Fexample-return%3Ftoken%3D%3Ctoken%3E